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Why so many Core i7-2600 flavours?

Posted on 9th Aug 2011 at 11:35 by Clive Webster with 26 comments

Clive Webster
There’s an interesting article over at Ars Technica, titled What processor should I buy: Intel’s crazy pricing makes my head hurt. That might seem a silly question at first: as the author points out, surely you just buy the most expensive CPU in the LGA1155 range. However, Peter Bright is no fool; looking closer at the specs and his requirements, the author struggles to make sense of Intel’s strategy with new features, performance and compatibility.

The problem is due to Bright’s desire to make a future-proof, fast PC that can run Visual Studio and Battlefield 3 easily. A Core i7-2600 is a no-brainer, but there are three flavours, with the S model even running at slower stock speeds to save 30W of power (it Turbo Boosts to the same 3.8GHz as the other i7-2600 CPUs, however).

Then there’s the toss-up between the i7-2600 and the i7-2600K – the former has some interesting virtualisation and security features that Bright wants, but the latter has a better GPU and the ability to overclock. So which one is better? They both seem compromised and yet there’s a £10 ($23) price difference. The point is really, why has Intel disabled the useful VT-d and the potentially useful TXT logic from the i7-2600K?

Sure, TXT could be seen as a way to introduce hardware-based DRM to a home PC, but as Bright points out, it could also be very useful in preventing rootkits from slaving your PC to their nefarious desire (my melodramatic wording, not his).

Bright finds a solution to his quandary in the Xeon world, where there is a CPU that fits his needs, but then he’s stymied by the lack of Smart Response on official Xeon chipsets. So he’ll have to opt for the not officially supported combination of a Z68 motherboard with a Xeon processor. This should work fine, but for a PC you absolutely rely on for work (I assume) this isn’t a comfortable arrangement.

So why does Intel feel the need to disable potentially useful features from its supposedly top-end CPU when this will slow down uptake? And is the lack of Smart Response technology in any Xeon chipset a tacit admission that it’s not 100 per cent reliable? Conspiracy theories below please!

26 Comments

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r3loaded 11th August 2011, 10:33 Quote
I too came across the lack of VT-d on the 2500K while analysing CPU specifications on Intel ARK. The 2500 has it, but the 2500K doesn't. I eventually decided that overclocking and gaming were more important to me than virtualisation, so I chose the 2500K. Doesn't make it any less annoying though.
RedFlames 11th August 2011, 10:52 Quote
there are 4 flavours of 2500, just to make things even more complicated...

the K - overclocking, better igp, lacks some business-orientated bits [vPro, VT-d]

the vanilla

the S - lower TDP, lower speed [same turbo speed]

the T - even lower TDP, even lower speed [and lower Turbo], lower igp frequency

EDIT: mis-read, you're on about the 2600, the above still applies, except there is no T version of the 2600
Ph4ZeD 11th August 2011, 10:52 Quote
Welcome to lack of competition :) Intel's decisions do seem nonsensical, but they know they can get away with it.
PQuiff 11th August 2011, 11:00 Quote
close your eyes. out stretch both arms. start spinning.......stop, choose a chip name/features.

Thats how intel does it.
wuyanxu 11th August 2011, 11:05 Quote
just checked, my CPU can overclock AND also have the said two features :p

competition Bulldozer can't get here soon enough
Madness_3d 11th August 2011, 11:06 Quote
Because you're not looking at their complete range. The 2600K is not their fastest chip. The new 2011 chips will hit the top of the range. Everything below the extreme version will have some level of compromise
mclean007 11th August 2011, 13:23 Quote
Quote:
Originally Posted by Madness_3d
Because you're not looking at their complete range. The 2600K is not their fastest chip. The new 2011 chips will hit the top of the range. Everything below the extreme version will have some level of compromise
Fine, but (a) they're not available now, so in the consumer space you're forced to choose between overclocking and VT-d/TXT, not both (the better IGP probably isn't a big concern at the high end); and (b) given the different feature sets, why do they share the 2600 name? If it was just that one was unlocked (2600-K) and the other (2600) not, that would be fair, but since the 2600-K also lacks something in the 2600, it seems a bit misleading.
mucgoo 11th August 2011, 13:28 Quote
I think the strangest decision is putting the better IGP within enthusiast K edition hardware while not putting it in the basic versions were the IGP will be used.

Intel realise a 2500k without IGP and use some of that production saving to cut prices by £10?
Roskoken 11th August 2011, 14:02 Quote
Its pretty simple, if your a busines paranoid about security use VT-d

If your a gamer, overclock with a K

Thats about it really.
Glix 11th August 2011, 14:30 Quote
K for cut? :p
lamboman 11th August 2011, 14:37 Quote
It can be confusing, but not misleading IMO.

I've thought it was a bit obvious myself to be honest, with the letters representing different features. They're essentially different ranges, just a bit jumbled. From Wiki:
Quote:
Originally Posted by Wikipedia
  • S processors feature lower-than-normal TDP (65 W on 4-core models).
  • T processors feature an even lower TDP (45 W on 4-core models or 35 W on 2-core models).
  • K processors have unlocked turbo multiplier and are designed for overclocking. Other processors will have limited turbo overclocking on a P67 chipset. K processors don't have Intel VT-d and TXT technologies support.

They should have put the letters before the name, but as I said, view them as separate ranges and it isn't a problem. So I completely disagree with the article on that front.

They should have left the virtualisation features on the K models, however.
azrael- 11th August 2011, 16:05 Quote
One could also argue why Intel gets away with selling the Cougar Point chipset in 57 different flavours (like Heinz ketchup), when there's really only one, and bits get fused off as needed ("market demand").
thehippoz 11th August 2011, 16:40 Quote
yeah that's pretty lame you have to choose between overclocking and having virtualization support

heck even the g6950 has virtualization. I use it all the time too
RedFlames 11th August 2011, 16:44 Quote
the K does still have VT-x, but not VT-d
thehippoz 11th August 2011, 17:01 Quote
oh nm.. your right red
ZERO <ibis> 11th August 2011, 22:51 Quote
If I am buying a xeon I likely am using a SSD for my c:/ drive so why would I need smart response....
moo123 12th August 2011, 01:28 Quote
"The problem is due to Bright’s desire to make a future-proof, fast PC that can run Visual Studio and Battlefield 3 easily."

Intel didn't design Sandy Bridge to be the jack-of-all-trades, this was obviously some marketing decision intended to increase volumes by having "specialized" processors. Either way, I've never been a fan of using a single computer for both work and game.There's just some comfort in having another computer with all your confidential files/designs/etc that your friends and family know not to touch.
Madness_3d 12th August 2011, 02:49 Quote
Quote:
Originally Posted by mucgoo
I think the strangest decision is putting the better IGP within enthusiast K edition hardware while not putting it in the basic versions were the IGP will be used.

Intel realise a 2500k without IGP and use some of that production saving to cut prices by £10?

They would save very little if any money. Chances are if the Chip is good enough to be highly overclockable (remember Intel are binning all their Sandybridges) then the IGP also works solidly. It would be pointless to disable bits of it if they're good chips, it wouldn't gain them anything or save them anything. At least this way, anyone who is just out for CPU performance (they do exist) also gets the gain of having all 12 EU's available, even if it is only for Video Encoding or the like. Makes more sense now that Z68 is out and we can see the bigger picture.

Quote:
Originally Posted by mclean007
Fine, but (a) they're not available now, so in the consumer space you're forced to choose between overclocking and VT-d/TXT, not both (the better IGP probably isn't a big concern at the high end); and (b) given the different feature sets, why do they share the 2600 name? If it was just that one was unlocked (2600-K) and the other (2600) not, that would be fair, but since the 2600-K also lacks something in the 2600, it seems a bit misleading.

I see your point. Technically Intel's leading chip atm is the 990X which supports VT-d but not TXT. As has been said they're catering to more than just the consumer market and you've also got to put it in perspective as a relative scale. Of the S chips, this is the 2600 of the S Series, it supports such and such. The S for example, also has embedded options available and so really can't be put in the same box as other normal chips. All that considered it shares alot with the normal 2600. By the same logic you could say that the i7-2620M should be faster and have the same feature set as the desktop 2600's. But again it's relative to other M chips.
Anyway, on the feature front, what Intel are really saying is, If you want VT-d, TXT and Overclocking then you're going to have to pay "Extreme" prices for it when they're released, and they can do that because they have such massive market dominance in the high performance sector.
jrs77 12th August 2011, 03:12 Quote
The biggest mistake was to have the HD3000 only in the K-versions. It's a no-brainer that people who buy the K-version will use a dedicated GPU. The HD3000 would be a perfect match for an i3-2100T tho, as this would be an awesome CPU for a HTPC.
And can someone explain, why all of the notebook-parts have the HD3000 in that regard, while the desktop-parts do not?

It's all a total mess, and that doesn't count for intel alone.
phuzz 12th August 2011, 11:55 Quote
So what you're all saying is: "It's not confusing when you know what all the different letters mean", which kind of misses the point of the article.
Madness_3d 12th August 2011, 12:14 Quote
Can someone give me an example of something which is well named? Seems like if it's not Intel it's Nvidia we're having a go at for their naming system :)
Hakuren 12th August 2011, 14:37 Quote
Well you can say typical Intel. I understand models where you can reduce power drain, but I don't get it why K version isn't VT compatible. It doesn't make sense at all.

Still for home user that is not a big deal. If you want to setup virtual machine (e.g. for XP) then there is always Virtual Box.
azrael- 12th August 2011, 15:54 Quote
Quote:
Originally Posted by Hakuren
Well you can say typical Intel. I understand models where you can reduce power drain, but I don't get it why K version isn't VT compatible. It doesn't make sense at all.

Still for home user that is not a big deal. If you want to setup virtual machine (e.g. for XP) then there is always Virtual Box.
All "2nd generation" Core i processors can be virtualized in the commonly known sense. That's what Intel calls VT-x. What the K versions funnily do not support, when more lowly versions do, is VT-d or I/O virtualization.
thewelshbrummie 13th August 2011, 17:50 Quote
It has VT-x support - at least Intel seem to include it on all their CPUs now. As said previously though, it doesn't support VT-d - which apparently is a PCI-passthrough & allows a virtual PC access to PCI/PCI-E cards.

It's a masssive mistake for Intel not to support it on the K CPUs. Rather than dual-booting XP/7 as I currently do, with VT-d support I could simply install 7 & then install XP as a virtual PC with it having access to my GPU for gaming (and gaining from not having to accomodate XP with the correct BIOS settings (lack of ACHI support and NCQ on HDDs being a good example)). Surely disabling such an important feature on a CPU that is most likely going to be used in gaming rigs is a major fail...
Durtey 14th August 2011, 18:28 Quote
It's cheaper to mass-produce one chip with all the features and then disabling the ones you don't want to use for the different models later.
The 2500k was never meant to have the disabled features so they turned them off.
kent thomsen 20th August 2011, 22:19 Quote
Isn´t it about saving the consumers appetite for Ivy Bridge?
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